U.S. Mistakenly Downs 2 Army Copters Over Iraq : Mideast: 15 of the 26 dead are Americans. Despite good visibility, F-15s target Blackhawks as Iraqi craft in 'no fly' zone. Pentagon is baffled. Clinton vows to 'get the facts.'

WASHINGTON — Two U.S. jet fighters mistakenly shot down a pair of U.S. Army helicopters over northern Iraq early Thursday morning, killing 15 Americans and 11 foreign officials in an episode that left U.S. military officers baffled as to how the tragedy could have occurred.

U.S. officials said the helicopters, both Army UH-60 Blackhawks, were ferrying a team of foreign officers and Kurds on a routine visit to remote Kurdish villages. They said the pilots of the U.S. jets--both Air Force F-15C Eagles--somehow mistook the helicopters for Iraqi aircraft despite good visibility.

President Clinton expressed "deep sorrow" over the tragedy and pledged to "get the facts" to the American people and to U.S. allies.

The downing of the helicopters occurred despite elaborate procedures established by the military to prevent such misidentifications.

All four aircraft were under the control of an Airborne Warning and Control System (AWACS) command plane, and the pilots had rehearsed their duties. Blackhawk helicopters also normally are equipped with electronic devices that identify them to friendly aircraft.

Although Pentagon officials declined to describe current rules of engagement--for fear of compromising military security--experts said the jet pilots probably were required to receive the approval of AWACS controllers and to identify the aircraft visually before opening fire.

Although indications were that the pilots had fulfilled both conditions, analysts suggested that either the pilots had made a mistake in identifying the aircraft or had spoken to a different controller aboard the AWACS than had the helicopter pilots.

The incident was all the more startling because the area where it happened--the "no fly" zone from which Iraqi aircraft are excluded under terms set by the allies at the end of the Persian Gulf War--has been quiet for more than a year. The last time a U.S. plane shot at an Iraqi aircraft over the region was in December, 1992, when a U.S. F-16 shot down a Soviet-made MIG fighter.

In Thursday's action, both of the Blackhawk helicopters were downed by U.S. missiles. One of the F-15Cs used a radar-guided AMRAAM missile, while the other used a Sidewinder, which homes in on the heat from its target--in this instance, the helicopter's engine.

U.S. officials said that an American search-and-rescue mission recovered all 26 bodies, and the U.S. European Command, which oversees allied air operations in the region, is dispatching a team of high-level investigators to the crash site today.

Pentagon officials did not hide their bewilderment over how the tragic mistake had occurred.

"Clearly something went wrong," Gen. John M. Shalikashvili, chairman of the Joint Chiefs of Staff, told reporters at a briefing.

Apart from the human tragedy, the episode was a setback for the military, which has been enforcing a "no fly" zone in the region for more than three years without major accidents.

The zone, established by the United States and its allies in April, 1991, was set up to protect Kurds in northern Iraq from raids by Iraqi troops. Iraqi aircraft are prohibited from flying in the zone.

Thursday's episode occurred in a barren region 35 miles north of Irbil, an Iraqi city near the Turkish border. U.S. military teams landed at the crash site later and were guarding it while the investigation was under way.

Military officials said there were no survivors. The recovered bodies were flown to a U.S. air base in Turkey. The Pentagon said the names of the dead will probably not be made public until today.

The 11 foreigners aboard who were killed consisted of two Britons, one Frenchman, three Turks and five Kurdish leaders. Most of the passengers apparently were military officers who were assigned to U.N. military and relief efforts for the Kurds.

Defense Secretary William J. Perry postponed a scheduled trip to South Korea today because of the incident.

Perry told the Public Broadcasting System's "MacNeil-Lehrer News Hour" later that he had ordered interim changes in the procedures used to enforce the "no fly" zone that he said are designed to "minimize the risk" until the actual cause of the accident is known.

He said investigators will probably be able to piece together a minute-by-minute account of the incident in a few days but warned that it could take longer to uncover the underlying problem. "It's clear that there were some serious errors made," the secretary said.

Army Lt. Gen. Richard F. Keller, chief of staff of the U.S. European Command, said it was not immediately clear whether the allies will continue their patrols without interruption.

But officials said later that the United States has no plans to abandon enforcement of the "no fly" zone, particularly in view of stepped-up harassment of the Kurds by Iraqi forces in the last few months.

Besides the "no fly" zone in the north, the allies have set up a similar flight ban in southern Iraq, this one to protect Shiite Muslims, who also have been the target of Iraqi attacks.